Ionic diol, antistatic polyurethane, and method of making the same
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Solution Overview
Problem
Current antistatic agents are ineffective at low humidity, lack thermal stability, and are not compatible with non-polar polymers, leading to inadequate performance and durability issues in industrial applications.
Innovation Solution
Development of ionic diols and antistatic polyurethanes with specific molecular structures that can be incorporated into coatings and polymer melt compositions, providing enhanced electrical conductivity and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If humectant-based antistatic agents are used, then electrical conductivity is improved through moisture adsorption, but effectiveness is diminished at low atmospheric humidity
Solution Approach 1:
The patent changes the fundamental mechanism from moisture-dependent conductivity to intrinsic ionic conductivity through quaternary ammonium salts. This parameter change allows the antistatic agent to maintain effectiveness across varying humidity levels, resolving the contradiction between reliability and adaptability to humidity conditions.
Solution Approach 2:
The quaternary ammonium salt acts as an intermediary that provides ionic conductivity without relying on atmospheric moisture. The permanent positive charge on the nitrogen atom attracts counterions that enable charge dissipation, serving as a mediator that decouples antistatic performance from humidity-dependent moisture adsorption.
2Reliability
If low molecular weight neutral antistatic agents are used, then electrical conductivity is improved, but thermal stability is insufficient to survive polymer melt processing
Solution Approach 1:
The patent creates a composite structure by combining the quaternary ammonium salt with a polymeric carrier or incorporating it into the polymer matrix. This composite approach maintains the electrical conductivity of the ionic agent while the polymeric structure provides thermal stability sufficient for melt processing, resolving the contradiction between conductivity and thermal stability.
3Reliability
If water-soluble antistatic agents are used, then electrical conductivity is improved, but durability is reduced due to easy removal by water exposure
Solution Approach 1:
The patent changes the solubility parameter by using hydrophobic alkyl chains (C12-C22) attached to the quaternary ammonium group. This parameter change makes the agent compatible with non-polar polymers and resistant to water removal, simultaneously maintaining ionic conductivity and improving durability through hydrophobic interactions with the polymer matrix.
4Reliability
If metal salts are used as antistatic agents, then electrical conductivity is improved, but compatibility with non-polar polymers is poor resulting in reduced physical properties
Solution Approach 1:
The patent changes the polarity parameter by replacing ionic metal salts with quaternary ammonium salts featuring long hydrophobic alkyl chains. This parameter change enables compatibility with non-polar polymers through hydrophobic interactions while maintaining ionic conductivity through the permanent charge on the nitrogen atom and associated counterions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The antistatic polyurethanes exhibit rapid static decay times and improved durability, maintaining effectiveness across varying humidity levels and temperatures, while being compatible with a range of polymer matrices.
Implementation Method 1
The buildup of electrostatic charge on insulating objects is especially common and problematic under conditions of low humidity and when liquids or solids move in contact with one another (tribocharging). Static charge build-up can be controlled by increasing the electrical conductivity of a material. This can be accomplished by increasing ionic or electronic conductivity.
Implementation Method 2
Antistatic agents operate by dissipating static charge as it builds up; thus, static decay rate and surface conductivity are common measures of the effectiveness of antistatic agents.
Data Source
AI summary
An ionic diol has formula wherein R1 represents an alkyl group having from 6 to 18 carbon atoms; R2 and R3 independently represent alkyl groups having from 1 to 4 carbon atoms; R4 represents an alkylene group having from 2 to 8 carbon atoms; and R5 represents an alkylene group having from 1 to 8 carbon atoms. Antistatic polymers are formed by copolymerization of monomers including a diisocyanate, an ionic diol, a polyether diol, and at least one non-ionic diols. Methods of making the antistatic polyurethanes are also disclosed.